Robot vacuum shows E4 and stops near stairs or edges.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Dust or pet hair on cliff sensors, Sensor window scratched, Failed cliff sensor PCB, Loose wiring to sensors

Safety first: Turn off the robot and place it upside down.

Clean cliff sensors: Gently wipe each downward‑facing sensor with a soft cloth. Use a dry cotton swab for tight areas.
Avoid dark surfaces: Test the robot on a light‑colored floor; very dark carpets can sometimes be misread as cliffs.
Check for physical damage: If any sensor window is cracked or missing, the sensor board must be replaced.
Persistent E4: Indicates a likely sensor or wiring fault requiring professional repair.

Medium 3/5

Cliff Sensor Board

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